fixed selection, added test (#3254)

src/canvas.class.js

@@ -118,13 +118,23 @@
 
     /**
      * Indicates which key enable multiple click selection
-     * values: altKey, shiftKey, ctrlKey
+     * values: altKey, shiftKey, ctrlKey, cmdKey
      * @since 1.6.2
      * @type String
      * @default
      */
     selectionKey:           'shiftKey',
 
+    /**
+     * Indicates which key enable alternative selection
+     * in case of target overlapping with active object
+     * values: altKey, shiftKey, ctrlKey, cmdKey
+     * @since 1.6.5
+     * @type null|String
+     * @default
+     */
+    altSelectionKey:           null,
+
     /**
      * Color of selection
      * @type String
@@ -398,7 +408,6 @@
           vptPointer = this.restorePointerVpt(pointer),
           p = fabric.util.transformPoint(vptPointer, invertedM);
       return fabric.util.transformPoint(p, vpt);
-      //return { x: p.x * vpt[0], y: p.y * vpt[3] };
     },
 
     /**
@@ -1006,22 +1015,34 @@
       var ignoreZoom = true,
           pointer = this.getPointer(e, ignoreZoom),
           activeGroup = this.getActiveGroup(),
-          activeObject = this.getActiveObject();
+          activeObject = this.getActiveObject(),
+          activeTarget;
 
       // first check current group (if one exists)
       // active group does not check sub targets like normal groups.
       // if active group just exits.
       if (activeGroup && !skipGroup && this._checkTarget(pointer, activeGroup)) {
         return activeGroup;
       }
-
-      if (activeObject && this._checkTarget(pointer, activeObject)) {
+      // if we hit the corner of an activeObject, let's return that.
+      if (activeObject && activeObject._findTargetCorner(pointer)) {
         return activeObject;
       }
+      if (activeObject && this._checkTarget(pointer, activeObject)) {
+        if (!this.preserveObjectStacking) {
+          return activeObject;
+        }
+        else {
+          activeTarget = activeObject;
+        }
+      }
 
       this.targets = [];
 
       var target = this._searchPossibleTargets(this._objects, pointer);
+      if (e[this.altSelectionKey] && target && activeTarget && target !== activeTarget) {
+        target = activeTarget;
+      }
       this._fireOverOutEvents(target, e);
       return target;
     },

src/mixins/object_geometry.mixin.js

@@ -355,6 +355,10 @@
       return this;
     },
 
+    /*
+     * calculate rotation matrix of an object
+     * @return {Array} rotation matrix for the object
+     */
     _calcRotateMatrix: function() {
       if (this.angle) {
         var theta = degreesToRadians(this.angle), cos = Math.cos(theta), sin = Math.sin(theta);

test/unit/canvas.js

@@ -346,17 +346,23 @@
   test('findTarget preserveObjectStacking true', function() {
     ok(typeof canvas.findTarget == 'function');
     canvas.preserveObjectStacking = true;
-    var rect = makeRect({ left: 0, top: 0 }),
-        rectOver = makeRect({ left: 0, top: 0 }),
+    var rect = makeRect({ left: 0, top: 0, width: 30, height: 30 }),
+        rectOver = makeRect({ left: 0, top: 0, width: 30, height: 30 }),
         target,
-        pointer = { clientX: 5, clientY: 5 };
+        pointer = { clientX: 15, clientY: 15, 'shiftKey': true },
+        pointer2 = { clientX: 4, clientY: 4 };
     canvas.add(rect);
     canvas.add(rectOver);
     target = canvas.findTarget(pointer);
     equal(target, rectOver, 'Should return the rectOver, rect is not considered');
     canvas.setActiveObject(rect);
     target = canvas.findTarget(pointer);
-    equal(target, rect, 'Should return the rect, because it is active');
+    equal(target, rectOver, 'Should still return rectOver because is above active object');
+    target = canvas.findTarget(pointer2);
+    equal(target, rect, 'Should rect because a corner of the activeObject has been hit');
+    canvas.altSelectionKey = 'shiftKey';
+    target = canvas.findTarget(pointer);
+    equal(target, rect, 'Should rect because active and altSelectionKey is pressed');
     canvas.preserveObjectStacking = false;
   });